Exeter was built by the Romans, who called it Isca Dumnoniorum (Isca of the Dumnonii, the local British tribe). After the Romans left and the Anglo-Saxons moved into the area in the seventh century, the name changed to Exeter. In the 1060s, Exeter was a centre of resistance to the Norman conquest. In 1050, the Bishop of Crediton moved to Exeter; from then until 1876 the bishops were the heads of the church in the whole of Devon and Cornwall. Now, only Devon is within the Exeter diocese.